Side Plank Oblique Crunch

How to do the Side Plank Oblique Crunch

1. 1Lie on your side on the floor and prop yourself up on your bottom forearm, with your elbow directly beneath your shoulder.
2. 2Stack your feet on top of each other and lift your hips off the floor so your body forms a straight diagonal line from head to feet.
3. 3Extend your top arm toward the ceiling or rest your top hand lightly behind your head with your elbow pointing upward.
4. 4Brace your core and squeeze your glutes to maintain a stable side plank position before beginning the crunch.
5. 5Exhale and simultaneously drive your top knee up toward your torso while bringing your top elbow down to meet it, crunching through the obliques.
6. 6Pause briefly at the top when your knee and elbow are as close together as your range of motion allows.
7. 7Inhale and reverse the movement in a controlled manner, extending your leg back out and returning your arm to the starting position.
8. 8Complete all reps on one side, then carefully lower your hips and switch sides to repeat.

Form tips

• Keep your bottom hip lifted throughout the entire set — letting it sag between reps kills the lateral tension on your obliques and adductors.
• Initiate the crunch from your obliques and glute medius rather than just swinging your leg; think 'compress the side of your waist' as the knee rises.
• Keep your neck neutral by looking straight ahead rather than craning up toward your elbow during the crunch.
• Move at a deliberate, controlled tempo — rushing the rep turns it into a momentum exercise and reduces oblique activation.
• If stacking your feet feels unstable, stagger the top foot slightly in front of the bottom foot to widen your base while you build strength.

Common mistakes

• Letting the bottom hip drop between reps, which eliminates the lateral plank tension and reduces activation of the gluteus medius and obliques.
• Rotating the torso forward during the crunch, turning a lateral flexion movement into a rotation — this shifts load off the target muscles and strains the lower back.
• Using momentum to swing the knee up rather than contracting the obliques, which reduces time under tension and lowers the effectiveness of the exercise.
• Placing the supporting elbow too far in front of or behind the shoulder, which creates instability and puts unnecessary stress on the shoulder joint.
• Holding your breath throughout the movement, which increases intra-abdominal pressure and reduces core control — exhale on the crunch, inhale on the return.

Frequently asked questions